Inventories (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Inventory [Line Items]
Raw material	$ 1,003
Work-in-process	7,386
Finished goods	79,938
Supplies	1,488
Total inventories	$ 89,815
Predecessor
Inventory [Line Items]
Raw material		$ 879
Work-in-process		6,093
Finished goods		3,689
Supplies		1,532
Total inventories		$ 12,193